#
# File:: levels.rb
# Description:: Levels.xml and <level>.dat file parser.
#
# Author:: David Muir <david.muir@rockstarnorth.com>
# Date:: 26 November 2008
#

#----------------------------------------------------------------------------
# Uses
#----------------------------------------------------------------------------
require 'pipeline/os/path'
require 'pipeline/util/string'
require 'rexml/document'

#----------------------------------------------------------------------------
# Implementation
#----------------------------------------------------------------------------
module Pipeline

	#
	# == Description
	# The Pipeline::Levels class defines a levels.xml parser and <level>.dat file
	# parser for fetching information about a level.  The concept of levels was
	# first introduced in Jimmy.
	#
	class Levels
		attr_reader :project		# Project reference
		attr_reader :branch			# Branch reference
		attr_reader :filename		# String filename of levels.xml file.
		attr_reader :levels			# Hash of level uiname to Level objects.
		
		def initialize( project, branch, filename )
			throw ArgumentError.new( "Invalid project object (#{project.class})." ) \
				unless ( project.is_a?( Pipeline::Project ) )
			throw ArgumentError.new( "Invalid branch object (#{branch.class})." ) \
				unless ( branch.is_a?( Pipeline::Branch ) )
			project.load_config( )
			
			@project = project
			@branch = branch
			@filename = filename
			@levels = {}
			
			File.open( @filename ) do |fp|
				xmldoc = REXML::Document.new( fp )
				xmldoc.elements.each( 'levels/level' ) do |xml_node|
				
					level = Level::from_xml( xml_node, self )
					throw RuntimeError.new( "Duplicate level data, key #{level.uiname} already used." ) \
						if ( @levels.has_key?( level.uiname ) )
					
					@levels[level.uiname] = level
				end
			end
		end
	end
	
	#
	# == Description
	# The Pipeline::Level class defines data read from the levels.xml file and
	# the <level>.dat file - essentially a mapping of file type to a filename.
	#
	# The filenames returned have environment values ready for substitution.
	#
	class Level
		attr_reader :levels			# Reference to owning Levels object.
		attr_reader :uiname			# Level friendlyname
		attr_reader :title			# Level title string
		attr_reader :dat_filename	# String filename of <level>.dat file.
		attr_reader :dat			# Hash of file type String keys to filenames
		
		def initialize( levels, uiname, title, dat_filename )
			@levels = levels
			@uiname = uiname
			@title = title
			@levels.branch.in_env do |env|
				@dat_filename = env.subst( dat_filename )
			end
			@dat = {}
		
			parse_dat( )
		end
		
		#
		# Create a Level object from an XML node.
		#
		def Level::from_xml( xml_node, levels )
			uiname = xml_node.attributes['friendlyName']
			title = xml_node.attributes['title']
			filename = xml_node.attributes['filename']
			filename.gsub!( 'common:', '$(common)' )
			
			Level.new( levels, uiname, title, filename )
		end
		
		#--------------------------------------------------------------------------
		# Private Methods
		#--------------------------------------------------------------------------
	private
		def parse_dat( )
			
			dat_data = []
			File::open( @dat_filename ) do |fp|
				dat_data = fp.readlines( )	
			end
			
			dat_data.each do |line|
				# Ignore comments and empty lines
				line.strip!
				next if ( 0 == line.size )
				next if ( line.starts_with( '#' ) )	
				
				# Replace common: and platform: with our environment tokens.
				line_dup = line.dup
				line_dup.gsub!( /common:/i, '$(common)' )
				line_dup.gsub!( /platform:/i, '$(platform)' )
				
				@levels.branch.in_env do |env|
					parts = line_dup.split( ' ' )
					key = parts[0].upcase
					file = env.subst( OS::Path::normalise( parts[1] ) )
					
					@dat[key] = [] unless ( @dat.has_key?( key ) )
					@dat[key] << file
				end
			end
		end
	end
end

# levels.rb